1. Field of the Invention
The present invention relates to liquid jetting apparatuses and liquid jetting methods.
2. Description of the Related Art
A liquid jetting apparatus is an apparatus to eject a liquid. The liquid jetting apparatuses include apparatuses such as printing apparatuses, color filter manufacturing apparatuses, and dying apparatuses. These liquid jetting apparatuses are provided with a head to eject a liquid. This head is made to eject the liquid toward a medium while being moved in a predetermined direction along a surface of the medium. For this reason, nozzles, which are ejection openings for the liquid, are provided on a medium opposing surface of the head. Furthermore, in order to eject a large amount of liquid in a short time, the nozzles are lined up in a row and configured in nozzle rows.
With this type of liquid jetting apparatus, it is required for the process of ejecting liquid to be shortened. For this reason, there is a tendency for the number of nozzles in each nozzle row to increase in relation to the head. For example, a head in which there are 180 nozzles per nozzle row has been proposed (see JP 2003-53968A, for example). If these nozzles are provided at a pitch corresponding to 180 dpi temporarily, then the length of the nozzle row is one inch (2.54 cm). There is also required greater speed in relation to the ejection frequency of the liquid (see JP 2003-326716A, for example). With these liquid jetting apparatuses, the movement speed of the head is increased along with increase in ejection frequencies of liquid.
With this type of liquid jetting apparatus, it is known that the droplets ejected from the nozzles separate and fly as main droplets and satellite droplets. In conventional apparatuses, the flight trajectory of the main droplets and the flight trajectory of the satellite droplets have a substantially fixed relationship, and the amount of displacement between the landing positions of both of these droplets is substantially fixed. For this reason, control of ejection that takes into account the displacement of the landing positions has been possible.
However, due to the above-mentioned increase in the number of nozzles per nozzle row, increased frequency of liquid ejection, and increased movement speed of the head, the satellite droplets fly greatly displaced from ordinary flight trajectories, and a phenomenon has been confirmed in which unexpected displacement in landing positions is caused. This unexpected displacement in landing position is a cause of various problems. For example, it is a cause of unevenness in color in printing apparatuses and textile printing apparatuses. It is also a cause of color mixing in color filter manufacturing apparatuses.